Thermoplastic copolymers of benzimidazolone and diepoxides



United States Patent ice Meme, 2, 1 13 3 495 255 n an alternate fashionthroughout the polymer chain. The THERMOPLASTIC bOPOLYMERS 0F BENZdiepoxides employed will preferably be derived from aro- IMIDAZOLONE ANDDIEPOXIDES matic or cycloaliphatic structures. The resulting linear PaulJ. George, West Richfield, Ohio, assignor to The thermoplastic P y areheat resist?! and Possess a B- F- Goodrich Company, New York, N.Y., acorhigh degree of stability. The polymers have high melting porafion f NY k points and are capable of being drawn into filaments, cast NoDrawing. Filed June 22, 1967, Ser. No. 647,965 into films as well asbeing useful for a variety of other US Cl. 260 2 Cosg 30/14 Claimscommon applications such as'coatings and the like.

10 DETAILED DESCRIPTION OF THE INVENTION The benzimidazolones (sometimescalled benzirnid- ABSTRACT OF THE DISCLOSURE azolones) which may bereacted to form the linear poly- Benzimidazolone and aromatic orcycloaliphatic dimers of the present invention correspond to thestructural epoxides are reacted to form linear thermoplastic polymll amers having good stability. The diepoxides especially use- 15 R ful arethose of the glycidyl ether type and those derived from epoxidizedolefins. The polymers of this invention Q are useful as protectivecoatings and can be drawn into BACKGROUND OF THE INVENTION 0 Thisinvention relates to novel polymers and more parwherein R represents ahydrogen or an alkyl group conticularly relates to thermoplasticcopolymers formed by taining from 1 to 18 carbon atoms, and preferablyconthe reaction of benzimidazolone with a diepoxide, pflrticlltainingfrom 1 to 8 carbon atoms. It is to be understood larly where the diepoxycompounds have aromatic or cythat the aromatic ring of thebenzirnidazolone may concloaliphatic structures. tain two or even morealkyl constituent as described The reactivity of the epoxy group and thefunctionality above and still fall within the scope of the presentinvenof compounds containing a plurality of epoxide groupings tion.Other groups which will not interfere with the rehas been widelyemployed to produce a variety of useful activity of the benzimidazoloneor interfere with the rematerials. For example, it is recognized thatamines, both action in any other way may al b b it t d on th aliphaticand aromatic, are useful curing agents for epoxy aromatic ring if sodesired. Such groups might also inhowever, highly cross-linked P ynetworks are elude aryl groups, alkoxy groups, nitro groups, halogensobtained when amine curing agents are used, and the re' o the like,

Suiting cured resins are of the thermos yp Amides, Diepoxides to bereacted with the benzimidazolone will however, do not serve as usefulcuring agents for epoxy have aromatic or cycloaliphatic structures. Ingeneral, resins. Amide curing agents have been found to be useful thediepoxides will be either glycidyl ether resins of the for epoxy resinsonly when free amines or amine de- Bisphenol A-epichlorohydrin type,having the structural composition products of the amide are present. 40formula SUMMARY OF THE INVENTION wherein n can be 0, in the simplestcase, or a positive in- I have now found that by reactingbenzimidazolones teger ranging up to about 20, or epoxidized olefinssuch with diepoxides, and preferably aromatic epoxides of the asvinylcyclohexene dioxide, bis(2,3-epoxycyclopentyl) glycidyl ether typeor cycloaliphatic diepoxides, that novel ether, the cycloaliphatic epoxyresin-carboxylate types, or linear thermoplastic polymers are produced.The forrnathe like. Excellent results have been obtained when the tionof the linear thermoplastic polymers of this invention epoxy compoundemployed was of the Bisphenol A- is possible due to the unique structureof the benzimidepichlorohydrin type in the molecular weight range upazolones which enables the achievement of a more conto about 5000. Thepolymer obtained when a benzimidtrollable reaction and thus prevents theformation of a azolone is reacted with a Bisphenol A-epichlorohydrinhighly cross-linked system. In addition to having a linear resin hasrecurring structural units of the formula structure, the polymers ofthis invention possess a high wherein R is a hydrogen or an alkylradical containing degree of stability due to the aromatic orcycloaliphatic from 1 to 18 carbon atoms, 11 may be 0 or a positivenature of the polymer backbone. integer up to about 20 and x is apositive integer.

In short, the polymers of this invention are formed by It is evidentfrom the above description that a wide the reaction of a benzimidazoloneand a diepoxide, Wherevariety of polymers may be prepared in accordancewith in the benzimidazolone and diepoxide units are arranged the presentinvention and consequently polymer properties will vary accordingly.This permits the formulation of polymers to meet specific demands whichmay arise. It should also be noted that with the benzimidazolone/Bisphenol A-epichlorohydrin resin polymers especially, that the polymerproperties can be modified not only by varying the ultimate molecularweight of the polymer but also by varying the value of n, i.e. byvarying the particular Bisphenol A-epichlorohydrin resin to be employed.

In conducting the reaction to form the linear thermoplastic polymers ofthis invention it is not absolutely essential that the benzimidazoloneand the diepoxide be employed in equivalent proportions; however, toform high molecular weight polymerizates it is best that the molar ratioof the reactants be about 1:1. A to 20% excess of either reactant may beemployed if desired; however, by maintaining a 1:1 mol ratio ofreactants the polymers obtained have higher molecular weights andgenerally better physical properties than polymers obtained when anexcess of one of the reactants is used. On this basis, it is thereforepreferable that the reactants be as pure as possible, that is, that theydo not contain unnecessary amounts of impurities or other materials thatwould interfere with the reaction. Likewise, the epoxide compound usedshould contain two epoxide groups per molecule or as close thereto aspossible to avoid undue cross-linking. Contaminants capable of reactingwith either of the reactants should be avoided in order to obtain highmolecular weight polymers. Catalysts may be employed to enhance thereaction of the epoxy compounds with the benzimidazolone, however,excellent results have been obtained in their absence. The reaction maybe conducted within a broad temperature range; however, it is generallypreferred that the reaction temperature range from about 20 C. to about350 C. Excellent results have been obtained at temperatures betweenabout 100 C. and 250 C. The reaction temperature will depend to a largeextent on the materials to be reacted, that is, the particularbenzimidazolone or diepoxide employed. The reaction is generally carriedout at atmospheric pressure; however, if desired, it may be conducted atpressures greater than atmospheric or at sub-atmospheric pressures. Itis often desirable to employ inert atmospheres of nitrogen, argon,helium or the like when carrying out the reaction.

It is not necessary to conduct the reaction in the presence of a solventor an inert diluent since many of the diepoxides are themselves liquidand serve as a convenient reaction medium. Even if both reactants aresolids, a solvent or diluent is still not required since excellentresults have been obtained by bulk polymerizations. This is not to saythat inert diluents or solvents cannot be employed, they are oftendesirable where the diluent employed is also a solvent for the reactantsand the resulting polymer. Such solvents might include: the aromatichydrocarbons and halogenated aromatic hydrocarbons; tertiary amines;N,N-disubstituted amides such as dimethyl formamide and dimethylacetamide; sulfones; lactones such as 'y-butyrolactone; ethers such asdiphenyl ether and tetrahydrofuran; nitriles; esters; or the like. Thereactions conducted with the inert diluents capable of dissolving theresulting polymer are often desirable since a polymer solution may beobtained directly and such polymer solution may be subsequently used tocast films or the like. The linear copolymers of the present inventionmay also be prepared by either batch or continuous methods. Such methodshave been adequately described in the literature.

The polymers of this invention are generally white, sometimes ranging toa yellow or yellow-brown depending on the purity of the reactants andthe reaction conditions employed. The polymers are generally soluble insolvents such as metacresol, dimethyl sulfoxide, dimethyl formamide,hexamethylphosphoric triamide and the like. Typically the polymer melttemperatures of the linear polymers will range from about C. to about350 C. and higher. The polymers are useful for a variety of applicationsincluding drawn filaments, films, castings, foils, adhesive applicationsand the like. They can be used as such or can be compounded withadditives such as fillers, pigments, dyes, lubricants, or other resins.If desirable, the polymers may be cured to a limited extent withconventional epoxy resin curing agents such as the diamines andpolyamines.

The following examples serve to illustrate the invention more fully;however, they are not intended to limit the scope thereof. All parts andpercentages are given on a weight basis.

Example I A polymer was prepared by reacting benzimidazolone with anepoxidized olefin. Benzimidazolone (0.71 part) was mixed with 1.27 partsof a resin of the cycloaliphatic epoxy carboxylate type having thestructural formula CH CH and a trace of 2,6-dimethylpyridine ascatalyst. The flask and its contents were heated between 200 and 250 C.for about 20 minutes with stirring. Nitrogen was passed through thesystem during the heating. Extremely long fibers were pulled from thepolymer. The fibers were glossy and had a tendency to be brittle.

Example II To demonstrate the preparation of a benzimidazolone/Bisphenol A-epichlorohydrin resin polymer, about 1.11 partsbenzimidazolone and 1.58 parts of a Bisphenol .A epichlorohydrin resinhaving an epoxide equivalent from 175 to 210 were mixed in a flask byheating in a flame. The flask was then sealed and maintained at atemperature of C. for 16 hours. The resulting polymer had a polymer melttemperature greater than 100 C. and fibers were pulled at C.

A portion of the polymer was dissolved in dimethyl formamide. The 25%solution was brushed onto an iron sheet and the solvent evaporated. Thedried polymer film formed a tough, thermal resistant protective coatingon the metal sheet.

Examples III-IV Example II was repeated except that small amounts of2,6-dimethyl pyridine was present in the reaction mixture. Polymersobtained were identical to that of Example II.

Example V To demonstrate the versatility of the present invention,benzimidazolone was reacted with an epoxy resin having a highermolecular weight. Benzimidazolone (020 part) and 2.77 parts of aBisphenol A-epichlorohydrin resin having an epoxide equivalent ofapproximately 925 were heated in a flask under a nitrogen atmosphere.Heating was continued with stirring until a temperature of 300 C. wasreached. Heating was continued at 300 C. for 5 minutes the reactionmixture allowed to cool to 125 C. and the heating cycle repeated again.Fibers having considerable strength were readily drawn from the polymermelt. The polymer melt temperature was 120 C.

The examples set forth above demonstrate that useful thermoplasticpolymers, capable of being drawn into fibers and of being used as films,can be prepared by reacting benzimidazolone with a diepoxy compound,wherein the diepoxide is one having an aromatic or cycloaliphaticstructure.

I claim: 7. A process for preparing a linear thermoplastic poly- 1. Alinear thermoplastic polymer comprising the remer which comprisesreacting a benzimidazolone having action product of a benzimidazolonehaving the structural the structural formula formula wherein Rrepresents hydrogen or an alkyl group containing from 1 to 18 carbonatoms, With an aromatic or wherein R is hydrogen or an alkyl radicalcontaining from cycloaliphatic vicinal diepoxide. l to 18 carbon atomswith an aromatic or cycloaliphatic 2. A polymer of claim 1, whereinbenzirnidaz l ne i8 vicinal diepoxide, in about a 1:1 mol ratio and at aemployed as a reactant. temperature of about 20 C. to about 350 C.

3. A polymer of claim 2, wherein the aromatic di- 8. A process of claim7, wherein the temperature is epoxide is a Bisphenol A-epichlorohydrinof the formula 20 between about 100 C. and about 250 C.

wherein n can be 0 or a positive integer up to about 20. 9. A process ofclaim 7, wherein the reaction is car- 4. A polymer of claim 2, whereinthe cycloaliphatic ried out in an inert organic diluent. diepoxide isderived from an epoxidized olefin. 10. A process of claim 7, wherein acatalyst is em- 5. A polymer of claim 4, wherein cycloaliphaticdiployed. epoxide is of the cycloaliphatic epoxy resincarboxylateReferences Cited type.

6. A polymer of claim 5, wherein the cycloaliphatic UNITED STATESPATENTS diepoxide has the structural formula 2,980,652 4/ 1961 Melamedet a1 WILLIAM H. SHORT, Primary Examiner 'L. E. NIELSEN, AssistantExaminer O 0 CH3 CHP US. Cl. X.R.

